The identification of natural, synthetic, and laboratory-treated gemstones presents an ongoing challenge to gemologists and jewelers. To address this problem, practical instruments are needed that will enable gemstones to be distinguished from one another quickly and easily.
Gemologists have traditionally used the visible spectra of gemstones to help in their identification. When light passes through a gemstone, a portion of the visible spectrum of the gemstone may be observed by means of a spectroscope enabling a viewer, to see the pattern of sharp absorption lines and broad regions of absorption and transmission that are often characteristic of a particular gem material.